A review on transition metal oxides based photocatalysts for degradation of synthetic organic pollutants.

This review provides insight into the current research trend in transition metal oxides (TMOs)-based photocatalysis in removing the organic colouring matters from water. For easy understanding, the research progress has been presented in four generations according to the catalyst composition and mode of application, viz: single component TMOs (the first-generation), doped TMOs/binary TMOs/doped binary TMOs (the second-generation), inactive/active support-immobilized TMOs (the third-generation), and ternary/quaternary compositions (the fourth-generation). The first two generations represent suspended catalysts, the third generation is supported catalysts, and the fourth generation can be suspended or supported. The review provides an elaborated comparison between suspended and supported catalysts, their general/specific requirements, key factors controlling degradation, and the methodologies for performance evaluation. All the plausible fundamental and advanced dye degradation mechanisms involved in each generation of catalysts were demonstrated. The existing challenges in TMOs-based photocatalysis and how the researchers approach the hitch to resolve it effectively are discussed. Future research trends are also presented.

Influences of Partial Destruction of Ti-MOFs on Photo(electro)catalytic H2 Evolution by Dominating Role of Charge Carrier Trapping over Surface Area.

The design of water-stable photo and electrocatalysts of metal-organic frameworks (MOFs) for its promising catalytic applications at long-term irradiations or persisted current loads is extremely necessary but still remains as challenging. A limited number of reports on Ti-MOF-based catalysts for water splitting are only available to explain and understand the correlation between the nature of materials and MOFs array. Herein, spherical Ti-MOFs and corresponding partially annealed hollow core-shell Ti-MOFs (Ti-MOF/D) are designed and the correlation with their photo(electro)catalytic water splitting performance is evaluated. The switchable valence state of Ti for the Ti-MOF as a function of molecular bonding is the possible reason behind the observed photocatalytic hydrogen generation and light-harvesting ability of the system. Besides, the defect state, solid core-shell mesoporous structure, and active sites of Ti-MOF help to trap the charge carriers and the reduction of the recombination process. This phenomenon is absent for hollow core-shells Ti-MOF/D spheres due to the rigid TiO2 outer surface although there is a contradiction in surface area with Ti-MOF. Considering the diversity of Ti-MOF and Ti-MOF/D, further novel research can be designed using this way to manipulate their properties as per the requirements.

Exploration and evaluation of proton source-assisted photocatalyst for hydrogen generation.

The present paper reports about the superior performance of some amine-based proton sources in enhancing the photocatalytic efficiency of Fe2O3-TiO2 composite during a water-splitting reaction. The band gap of the Fe2O3-TiO2 catalyst is tuned to 2.3 eV by varying the Fe content. The heterojunctions generated in the photocatalyst facilitate effective charge carrier migration suppressing the electron-hole recombination rate. The enhanced photocatalytic activity of the catalyst is studied using an experimental setup comprising a solar simulator (AAA) and a hydrogen gas chromatograph. The effect of proton sources viz, aniline hydrogen chloride (AH), diethylamine hydrogen chloride (DAH) and triethylamine hydrogen chloride (TAH), on the photocatalytic performance of the catalyst is explored and studied in detail. These proton sources serve as electron donors that stimulate photogenerated electron-hole separation that results in high quantum efficiency of the Fe2O3-TiO2 photocatalyst. A very high hydrogen generation rate of 880 µmol h-1 is achieved with the DAH-assisted Fe2O3-TiO2, whereas it is just 323 µmol h-1 with the Fe2O3-TiO2 alone. The enhancement in the hydrogen generation rate is attributed to the high basic nature, distinct hole scavenging action, low electron-hole recombination rate and the swift interfacial charge - transfer process. The effect of other proton source-assisted catalysts are also discussed in detail.

Synergistic action of Bacillus subtilis, Escherichia coli and Shewanella putrefaciens along with Pseudomonas putida on inhibiting mild steel against oxygen corrosion.

Microbial biofilm can effectively alter the electrochemical characteristics at metal/solution interface that can either accelerate or decelerate corrosion. The present paper reports about microbiologically induced corrosion inhibition (MICI) using Pseudomonas putida as a dominant bacterium under aerobic condition. Effective corrosion inhibition is achieved by the synergistic metabolic action of P. putida along with Escherichia coli, Bacillus subtilis or Shewanella putrefaciens. The synergistic metabolic actions of these bacteria in biopassivation are analysed with various aspects such as electrochemical impedance spectroscopy (EIS), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM) and confocal laser scanning microscopy (CLSM). Surface topography is quantitatively analysed using optical scanning profilometry (OSP). The binary culture system containing P. putida + E. coli and P. putida + S. putrefaciens achieves an inhibition efficiency of 90% and 85% respectively, despite S. putrefaciens being a corrosion causing bacteria. The P. putida + E. coli system could form a stable biofilm on mild steel surface, with a high corrosion potential (- 329 mV vs. Ag/AgCl/KCl sat'd) and a low corrosion rate (1.65 × 10-1 mmpy). The presence of B. subtilis in the culture promotes corrosion against normal predictions. In the present case, the metabolic activities of the bacterial system on the mild steel surface cause depletion of oxygen in the medium that leads to suppression of corrosion. In addition, the biofilm could form an effective protective barrier on the metal surface that can suppress diffusion of corrosion products resulting in enhanced corrosion inhibition efficiency.

Biochar supported Pseudomonas putida based globules for effective removal of Bisphenol A with a practical approach.

The widespread and inevitable use of plastic has led to prospective ecological problems through Bisphenol A (BPA), a synthetic chemical in plastic manufacturing. The present study addresses a unique methodology for eliminating BPA using the assistance of Pseudomonas putida. In the present work, biomass was torrefied to generate biochar with highly porous networks that could accommodate the bacterial species for effective colonization and multiplication. The designed biochar-bacterial globules demonstrated the ability to effectively remove BPA (96.88%) at a concentration of up to 2 g/L. The biochar-bacterial globules could effectively adsorb BPA at a low concentration of 20 mg/L. The alteration in pH did not impact the globule's performance, providing additional support for the practical utilization of these globules in polluted water bodies. In addition, the biochar-bacterial globules exhibited superior effectiveness in degradation compared to the standard levels, particularly in saline conditions. The simplicity and effectiveness of the approach make it promising for real-world implementation in addressing ecological problems associated with BPA contamination.

Tissue biomarkers of breast cancer and their association with conventional pathologic features.

BACKGROUND: Tissue protein expression profiling has the potential to detect new biomarkers to improve breast cancer (BC) diagnosis, staging, and prognostication. This study aimed to identify tissue proteins that differentiate breast cancer tissue from healthy breast tissue using protein chip mass spectrometry and to examine associations with conventional pathological features. METHODS: To develop a training model, 82 BC and 82 adjacent unaffected tissue (AT) samples were analysed on cation-exchange protein chips by time-of-flight mass spectrometry. For validation, 89 independent BC and AT sample pairs were analysed. RESULTS: From the protein peaks that were differentially expressed between BC and AT by univariate analysis, binary logistic regression yielded two peaks that together classified BC and AT with a ROC area under the curve of 0.92. Two proteins, ubiquitin and S100P (in a novel truncated form), were identified by liquid chromatography/tandem mass spectrometry and validated by immunoblotting and reactive-surface protein chip immunocapture. The combined marker panel was positively associated with high histologic grade, larger tumour size, lymphovascular invasion, ER and PR positivity, and HER2 overexpression, suggesting that it may be associated with a HER2-enriched molecular subtype of breast cancer. CONCLUSION: This independently validated protein panel may be valuable in the classification and prognostication of breast cancer patients.

Control of carbon monoxide (CO) from automobile exhaust by a dealuminated zeolite supported regenerative MnCo2O4 catalyst.

We synthesized MnCo(2)O(4) catalyst with very high porosity on the surface of dealuminated zeolite molecular sieves (DAZMS) for CO oxidation under actual automobile conditions. The MnCo(2)O(4) catalyst was selected on the basis of preliminary DFT study using the software ADF BAND. The MnCo(2)O(4) catalyst had comparatively higher CO adsorption energy and very low oxygen vacancy formation energy. The synthesized MnCo(2)O(4)/DAZMS catalyst was characterized by XRD, XRF, BET, SEM, and Confocal Microscopy. The Confocal microscopic analysis revealed that porosity of the dealuminated zeolite surface was significantly enhanced after the catalyst loading process. The completely precious metal free and DAZMS-supported catalyst exhibited excellent CO oxidation ability with renewed activity for seven months under actual automobile conditions with reference to normal and cold start conditions. The synthesized MnCo(2)O(4)/DAZMS not only exhibited surprisingly high catalytic activity for CO oxidation at a temperature resembling a cold start period but was also sufficiently stable/active under actual automobile conditions and ambient conditions containing large amounts of CO,H(2)O,CO(2), and NO(x) at 155-715 °C. These significant results revealed the flexible use of the present catalyst system for a wide variety of automobiles from a small gasoline-fuelled vehicle to a large diesel-fuelled vehicle that may produce high CO-content exhaust.

Effect of W-TiO2 composite to control microbiologically influenced corrosion on galvanized steel.

Microorganisms tend to colonize on solid metal/alloy surface in natural environment leading to loss of utility. Microbiologically influenced corrosion or biocorrosion usually increases the corrosion rate of steel articles due to the presence of bacteria that accelerates the anodic and/or cathodic corrosion reaction rate without any significant change in the corrosion mechanism. An attempt was made in the present study to protect hot-dip galvanized steel from such attack of biocorrosion by means of chemically modifying the zinc coating. W-TiO2 composite was synthesized and incorporated into the zinc bath during the hot-dipping process. The surface morphology and elemental composition of the hot-dip galvanized coupons were analyzed by scanning electron microscopy and energy dispersive X-ray spectroscopy. The antifouling characteristics of the coatings were analyzed in three different solutions including distilled water, seawater, and seawater containing biofilm scrapings under immersed conditions. Apart from electrochemical studies, the biocidal effect of the composite was evaluated by analyzing the extent of bacterial growth due to the presence and absence of the composite based on the analysis of total extracellular polymeric substance and total biomass using microtiter plate assay. The biofilm-forming bacteria formed on the surface of the coatings was cultured on Zobell Marine Agar plates and studied. The composite was found to be effective in controlling the growth of bacteria and formation of biofilm thereafter.

Physical activity, walking and leanness: an analysis of the Northern Ireland Sport and Physical Activity Survey (SAPAS).

OBJECTIVE: To report on the contribution walking makes to total weekly physical activity and the relationship between the volume and intensity of walking and leanness in a representative sample of the Northern Ireland population. METHOD: 4563 adults participated in this cross-sectional survey of physical activity behaviour. Self-reported height and weight was used to determine inverse body mass index (iBMI) as a measure of leanness. Data across all domains of physical activity including self-reported volume and intensity of walking (in bouts of 10 min or more) were analysed to determine their contribution to leanness using ANCOVA, having controlled for age, gender, socio-economic and smoking status. RESULTS: Over 68% of the participants reported walking >10 minutes during the previous week but only 24% report walking at a brisk or fast pace. Time walking at a brisk or fast pace for personal transport was identified as having the strongest positive association with being lean (F(1,4256)=10.45, ß=0.051 cm(2) kg(-1) min(-1) (SE=0.016),P=0.001). CONCLUSIONS: In addition to increasing the amount of walking and the percentage of people walking regularly, public health messages encouraging an increase in walking pace may be valuable to increase the proportion of the population meeting physical activity guidelines and gaining associated health benefits.

Evaluating the shelf-life of pasteurized milk in Oman.

The aims of this study were to survey the current storage condition of pasteurized milk in Oman and to evaluate its physicochemical and microbiological stability. The results of the statistical survey indicated that 50% of the total outlets surveyed were in violation in terms of providing the conditions for storing pasteurized milk, where grocery stores formed the majority of those outlets in violation. The results of physicochemical and microbiological tests of samples, which were stored at temperatures of 5 °C and 8 °C for a period of 12 days from the date of production, indicated that the characteristics of pasteurized milk were not affected during the storage period, and their results were consistent with the standard specifications of pasteurized milk. Therefore, extending the shelf-life of pasteurized milk stored at 5 °C for a period of 9 days from the date of production is considered safe.

Tuning of the electrocatalytic characteristics of PANI/Fe2O3 composite coating for alkaline hydrogen evolution reaction.

The paper reports a simple and cost-effective strategy for the development of a stable and reproducible PANI/Fe2O3 composite coating as an efficient electrode for the electrocatalytic alkaline hydrogen evolution reaction (HER). The surface characteristics of the developed PANI/Fe2O3 composite coatings are tuned to achieve high hardness (510 HVN), thickness (26 µm), porosity, and surface roughness (Sa = 3.760 µm). The PANI/Fe2O3 composite coating with tuned surface characteristics (PANI/Fe2O3-2GL) facilitates the effective conduction of electrons from a highly conducting polymer to a metal. This increases the electron density on the coating surface and enhances the active surface area, which effectively enhances the hydrogen adsorption efficiency on the coating surface to improve HER activity. The composite coating exhibits enhanced HER activity with low overpotential (110 mV) and high exchange current density (95.32 mA cm-2). The mechanism of HER on the coating surface follows the Volmer-Heyrovsky reaction with the Heyrovsky step as the rate-determining step. The stability of the composite coating under aggressive reaction conditions even after long-term HER confirms its competency with commercial electrocatalysts.

Anti-corrosion and microstructural properties of Ni-W alloy coatings: effect of 3,4-Dihydroxybenzaldehyde.

In the present work impact of 3,4-Dihydroxybenzaldehyde on the microstructural and corrosion behavior of nanocrystalline Ni-W alloy coatings has been elucidated. A systematic investigation on the protection ability of Ni-W alloy coatings in 0.2 M H2SO4 solution was done with the aid of tafel polarization curves and electrochemical impedance spectroscopy (EIS) studies. Corrosion performance of the alloy films obtained in the absence and in the presence of different concentrations of 3,4-Dihydroxybenzaldehyde (0-500 ppm) in the bath was explained in the light of additive concentration. Compared to the blank and other concentrations of additive, 250 ppm of additive containing bath was predicted as the most promising one for the introduced citrate based Ni-W alloy electrodeposition. Low corrosion rate (0.06 mm/year) and high charge transfer resistance (2505.3 Ω cm2), for the electrodeposits, obtained from the bath containing 250 ppm of 3,4-Dihydroxybenzaldehyde supports for its high anticorrosion performance. The marked difference in the corrosion resistance property is ascribed to the formation of fine-grained deposits, smooth surface, and inclusion or adsorption of additive within the deposits in the presence of the additive (250 ppm) in the bath. Further, the adsorption of additive molecules on the metal surface was explored with the help of quantum chemical calculations based on DFT.

Nano nickel oxide/nickel incorporated nickel composite coating for sensing and estimation of acetylcholine.

Pure nickel electrodes can be used as biosensors especially for sensing and estimating acetylcholine neurotransmitter. In the present work, a good electrochemical sensor was developed by electroplating nano nickel oxide reinforced nickel on graphite substrate. The morphology of the working electrode surface was studied by using a scanning electron microscope (SEM). The electrochemical and biological performance of the modified electrode was characterized by polarization studies in different media. The present modified electrode showed good sensing performance with a response time as low as 8s during sensing and estimation of acetylcholine. The sensitivity of the modified electrode was 34.88 microA/(microM cm(2)).

A novel method of coating orthodontic archwires with nanoparticles.

BACKGROUND: The major hazard to the orthodontic tooth movement is the friction developing at the bracket wire interface. In the past, there have been various attempts to reduce this friction. We believe that coating the commercially available orthodontic wires with nanoparticles can result in a successful reduction of this friction. The objective of this study is to develop a novel method of coating orthodontic archwires with nanoparticles. MATERIALS AND METHODS: Stainless steel (Ormco, CA, USA), titanium molybdenum alloy (Ormco, CA, USA) and nickel-titanium (G and H Wire Company, USA) orthodontic wires with a rectangular cross-section dimension of 0.019"× 0.025", were selected. The wires were later coated with a uniform and smooth nanoparticle film using 100 ml nanocremics. The coating procedure described in this article is a sol-gel thin film dip coating method. RESULTS: The coating procedure was verified by comparing the surface topography of nanocoated archwires with the commercially available archwires in an environmental scanning electron microscope (ESEM). The ESEM images prove that the surface topography of the coated wires was found to be smoother with less surface deteriorations as compared to the commercially available wires. CONCLUSION: Commercially available orthodontic wires can be successfully coated using a novel method of sol-gel thin film dip coating method.

Groin lymphorrhea postoperative nuisance.

Lymphorrhea is defined as the flow of lymph from disrupted lymphatic channels that drains externally or is contained within a wound. It complicates approximately 2% of vascular incisions in the groin. Of 116 patients who underwent different arterial reconstructions involving 186 groin wounds, lymphorrhea developed in 4 patients (3.4%) including 4 groins (2.1%). They have been managed in the Division of Vascular Surgery at King Khalid University Hospital (KKUH) in Riyadh, during a 3-year period ending in February 1996. There were 105 (90.5%) males and 11 (9.5%) females. The ages ranged from 32 to 96 years with a mean age of 63 years. All the 4 cases complicated with lymphorrhea were managed conservatively for a period of three to five weeks. In 2 cases, the lymphatic leak stopped and the patients discharged without other local complications. In the other 2 cases, lymphatic leakage stopped immediately and permanently following direct surgical ligation. The use of isosulphane blue for localization of the site of the lymphatic leak was a simple, reliable and accurate method during wound exploration. Follow-up of all cases for 6 months showed no recurrence, no sepsis and patent vascular graft.

Drug utilization patterns in the emergency department: A retrospective study.

OBJECTIVES: The aim of this study was to assess the prescribing trends and costs of drugs in the emergency department (ED) at Sultan Qaboos University Hospital (SQUH), a tertiary care hospital, in Muscat, the Sultanate of Oman. MATERIALS AND METHODS: This was a retrospective cross-sectional study of all patients (n = 300) who attended the ED at SQUH in May 2012. Analyses were performed using descriptive and univariate statistics. RESULTS: The average age of patients was 34 ± 19 years. The average number of drugs prescribed per patients was 3.2 ± 1.9 and the majority of the patients (n = 78; 26%) received two drugs. The most common route of drug administration was the oral route (n = 481; 51%) followed by parenterally (n = 357; 38%). Non-steroidal anti-inflammatory drugs (NSAIDs) were the most commonly prescribed class of drugs (38%) followed by the gastro-intestinal tract drugs (19%) and central nervous system drugs (13%). The average cost per prescription was 242 ± 632 US$. Morphine had the highest cost (1885 US$) followed by cefuroxime (1404 US$) and filgrastim (939 US$) over the 1-month period. There was a significant positive correlation between hospital cost and age (P < 0.001), duration of stay at the ED (P = 0.008) and emergency types (P < 0.001). CONCLUSION: NSAIDs were the most frequent class of drugs administered to patients. Highest number of drugs was prescribed for cardiovascular diseases followed by respiratory and gastrointestinal diseases. Anti-infective drugs cost was the highest among all other classes. The results of the present study are attempts to highlight the importance of strategies that have to be implemented to optimize medication use at the ED.

Development and evaluation of two PVD-coated ß-titanium orthodontic archwires for fluoride-induced corrosion protection.

The present research was aimed at developing surface coatings on ß titanium orthodontic archwires capable of protection against fluoride-induced corrosion. Cathodic arc physical vapor deposition PVD (CA-PVD) and magnetron sputtering were utilized to deposit thin films of titanium aluminium nitride (TiAlN) and tungsten carbide/carbon (WC/C) coatings on ß titanium orthodontic archwires. Uncoated and coated specimens were immersed in a high fluoride ion concentration mouth rinse, following a specially designed cycle simulating daily use. All specimens thus obtained were subjected to critical evaluation of parameters such as electrochemical corrosion behaviour, surface analysis, mechanical testing, microstructure, element release, and toxicology. The results confirm previous research that ß titanium archwires undergo a degradation process when in contact with fluoride mouth rinses. The study confirmed the superior nature of the TiAlN coating, evident as many fewer changes in properties after fluoride treatment when compared with the WC/C coating. Thus, coating with TiAlN is recommended in order to reduce the corrosive effects of fluorides on ß titanium orthodontic archwires.

A novel nano hydroxyapatite-incorporated Ni-P coating as an effective inter layer for biological applications.

Hydroxyapatite (HA) coatings are normally made directly on orthopaedic implants and they possess many demerits such as cracks, irregular phase composition and poor adhesion. The present study had a novel approach of providing a nano-HA and phosphorous-rich electroless nickel (EN) coating as an interlayer on stainless steel (SS) prior to electrodeposition of pure HA coating. The interlayer had the merits of having incorporated with nano HA with rich phosphorous content. The outermost HA coating had excellent adherence and it was found to be free from any defects since it was formed only on the interlayer and not on the direct substrate. The overall coating system revealed high bioactivity when immersed in simulated body fluid (SBF). The present study also highlights the scope of using cost effective SS as the implant substrate instead of titanium as against the current trend of substrate selection.

The role of calcium gluconate in electrochemical activation of titanium for biomimetic coating of calcium phosphate.

Supersaturation of calcium and phosphate in the bath solution and activation of the metal substrate is essential for effective biomimetic growth of apatite on orthopedic implants. In this work, bioactivation of titanium surface was achieved by electrodeposition of a thin layer of calcium phosphate followed by an alkaline treatment to obtain pure hydroxyapatite crystals. The influence of calcium gluconate in the electrolyte solution was evaluated and optimized. Adhesive strength, thickness, structural, and surface characteristics were evaluated. A highly adhesive and uniform layer of hydroxyapatite was formed on titanium surface when the electrodeposition was carried out with an electrolyte solution-containing calcium gluconate. The electrodeposited hydroxyapatite coatings were subjected for biomimetic growth in Kokubo's simulated body fluid (SBF) and Kokubo's modified SBF containing 1.5 times higher concentration of Ca. Biomimetic growth was also improved by the addition of calcium gluconate in the SBF solution.